Application of HOUSE WRAP in Steel Structure Building
Steel Structure Building is a common type of modern energy-saving house.Its overall wall is light, resistant to earthquakes, simple to install and flexible in design. Steel Structure is one of the most preferred materials for many large buildings.The HOUSE WRAP is an indispensable part of the steel structure house.Why?First let's look at the structure of a steel structure building.Steel structure houses are supported by the beams designed by the architect, while the insulation of steel structure houses is completed by rock wool, glass wool or other insulation materials.
Under normal conditions, different thermal insulation layers have different thermal resistance values, which can be selected according to different building types and regional climate.The thermal resistance of these insulation layers is measured when the insulation layer is dry. And only when the insulation layer is dry can the thermal resistance be guaranteed.Therefore, the waterproof protection for insulation layer is very important.The task is completed by the waterproof breathable membrane we will introduce below.
A. Working principle of ROOF MEMBRANE
1. Waterproof performance: ROOF MEMBRANE is a synthetic material, which is a kind of microporous membrane produced by the latest technology.Don't get me wrong, the so-called microporous membrane is not made by mechanical perforation, but by means of micro technology. The pore diameter of the microporous membrane is smaller than that of water molecules, so water cannot pass through the membrane.Therefore this product has the function of waterproof.
2.Breathable principle: why do ROOFING MEMBRANE need to be breathable?Because it is not enough to keep insulation dry only by resisting water. Even if the insulation layer can be completely waterproof, there will be water droplets formed inside the insulation. The principle is the same as the widow froze formed inside the windows in winter. Although the liquid water is blocked, the water vapor penetrated inside the insulation will also condensed into water when meeting cold air. So if the BREATHABLE ROOFING MEMBRANE is completely not breathable, the condensed water cannot discharge outside.In the long run, there will be bacterium breed inside the insulation, which will greatly influence the indoor air quality and cause serious health problems to homeowners.Therefore, the BREATHABLE ROOFING MEMBRANE must be breathable.So how does it breathe? The answer is quite simple----the size of the micro pores are larger than the size of the air molecules, so the water vapor can escape easily and dry out when the weather is clear or windy.
3. Heat preservation principle: BREATHABLE ROOFING MEMBRANE is just a thin membrane. How can it play the role of heat preservation?Let's start with the thermal resistance of the insulation.The thermal resistance value is measured when the inside air of the insulation is static and the insulation is dry. If there are some air flow inside the insulation, the thermal resistance value will reduce while the speed of air flow rise. This kind of problem cannot be solved by adding the thickness of the insulation. The only way to solve this problem is to use BREATHABLE ROOFING MEMBRANE to block the air outside. So it is very important to use BREATHABLE ROOFING MEMBRANE on steel structure buildings.
B.Installation tips for BREATHER MEMBRANE:
1. Make as few perforation as possible. If perforation must occur, use flashing up the perforation and seal with flashing tape.It doesn't matter if the nail is driven directly into the flashing tape, because the flashing tape won't lose its waterproof and air resistance performance on the nail place. But it is still better to add another layer of flashing tape outside the nail cap.
2. Lapping: the BREATHER MEMBRANE should be installed from the bottom to the top. The lapping should be at least 16cm, but not more than 30cm. It is better to use double sided butyl tape between two membrane laps. Then use flashing tape to stick outside. After installation, remember to use rolls to press the tape tightly. That will make it seamless between two membranes and get better waterproof performance.